Okay, maybe here's a good way to state our disagreement:

If a good-aligned character becomes "reasonably" convinced of a certain worldview, then acts in a manner befitting a good-aligned character vis-a-vis that worldview, must that character still be considered good-aligned?

If it were reasonable for my character to believe that every time a mage casts "detect invis" that a thousand elven babies die horrible deaths, I might not kill all mages outright, but I'd strongly consider it should they refuse to stop casting "detect invis". That's the "good-aligned" thing to do, given that particular belief system.

There are evil acts done by people who consider themselves "good", but in truth aren't. Then there are evil acts done by people who really are good, but are just horribly misguided. Take the mother who kills one of her children because she hallucinated that he was trying to kill the rest of her children. Is she "neutral" or "evil"? Or is she just a delusional goodie?

Or how about this. You have Joe Maran. He's a diligent guy, and destroys lots of really evil people. Unbeknownst to him, a group of Scions casts a powerful spell on him such that Orcs look like Elves and vice versa. Joe Maran then proceeds to kill lots of "orcs", which are actually elves. This was an evil act, in that he killed a slew of goodies. But he thought he was doing good, and had no way of knowing that wasn't the case. Should Joe Maran be turned evil (or neutral) in response to his heinous crimes?